Spinal implant system and method
A spinal construct comprises a member extending between a first end and a second end and includes a first layer and a second layer. The first layer includes a plurality of interlaced strands that define a first angle. The second layer includes a plurality of interlaced strands that define a second angle. The first angle is smaller than the second angle. Systems, implants, surgical instruments and methods are disclosed.
1. A spinal construct comprising:
a member extending between a first end and a second end and including a first layer and a second layer,
the first layer including a plurality of interlaced strands that define a first angle, and
the second layer including a plurality of interlaced strands that define a second angle,
the first angle being smaller than the second angle,
wherein the member has the same physical characteristics along the entire length of the member.
2. A spinal construct as recited in claim 1 , wherein the member comprises an anterior tether.
3. A spinal construct as recited in claim 1 , wherein the interlaced strands are braided.
4. A spinal construct as recited in claim 1 , wherein at least one of the layers is fabricated from UHMWPE.
5. A spinal construct as recited in claim 1 , wherein the first layer comprises a braid having a plurality of carriers including the interlaced strands, the carriers being oriented to define the first angle in a range of 15 through 65 degrees.
6. A spinal construct as recited in claim 5 , wherein the second layer comprises a braid having a plurality of carriers including the interlaced strands, the carriers being oriented to define the second angle in a range of 35 through 90 degrees.
7. A spinal construct as recited in claim 1 , wherein the first layer comprises a braid having a plurality of carriers including the interlaced strands, the carriers being oriented to define the first angle of 40 degrees.
8. A spinal construct as recited in claim 7 , wherein the second layer comprises a braid having a plurality of carriers including the interlaced strands, the carriers being oriented to define the second angle of 67 degrees.
9. A spinal construct as recited in claim 1 , wherein the first layer comprises a braid having a plurality of carriers including the interlaced strands, the carriers being oriented to define 1 through 25 picks per inch.
10. A spinal construct as recited in claim 9 , wherein the second layer comprises a braid having a plurality of carriers including the interlaced strands, the carriers being oriented to define 15 through 35 picks per inch.
11. A spinal construct as recited in claim 1 , wherein the first layer comprises a braid having a plurality of carriers including the interlaced strands, each carrier including 25 through 40 strands.
12. A spinal construct as recited in claim 11 , wherein the second layer comprises a braid having a plurality of carriers including the interlaced strands, each carrier including 25 through 40 strands.
13. A spinal construct as recited in claim 1 , wherein the member includes a tensile strength of greater than or equal to 1400 N.
14. A spinal construct as recited in claim 1 , wherein the member includes an elongation of less than or equal to 8% at a force application of 200 N.
15. A spinal construct as recited in claim 1 , further comprising a bone fastener defining an implant cavity configured for disposal of the member and a coupling member having a penetrating element extending through at least a portion of the member.
16. A vertebral tether comprising:
an inner braid including a plurality of carriers oriented to define a first angle in a range of 15 through 65 degrees and 1 through 25 picks per inch; and
an outer braid including a plurality of carriers oriented to define a second angle in a range of 35 through 90 degrees and 15 through 35 picks per inch,
wherein the tether has the same physical characteristics along the entire length of the tether.
17. A spinal construct comprising:
an anterior tether extending between a first end and a second end, the tether comprising a first layer including a plurality of interlaced strands that define a first angle and a second layer including a plurality of interlaced strands that define a second angle, the first angle being smaller than the second angle;
a bone fastener defining an implant cavity configured for disposal of the tether; and
a set screw having a penetrating element extending through at least a portion of the tether,
wherein the tether has the same physical characteristics along the entire length of the tether.
18. A spinal construct as recited in claim 17 , wherein the first layer includes a plurality of carriers oriented to define a first angle in a range of 15 through 65 degrees and 1 through 25 picks per inch, and the second layer includes a plurality of carriers oriented to define a second angle in a range of 35 through 90 degrees and 15 through 35 picks per inch.
19. A spinal construct as recited in claim 17 , wherein the tether includes a tensile strength of greater than or equal to 1400 N.
20. A spinal construct as recited in claim 17 , wherein the tether includes an elongation of less than or equal to 8% at a force application of 200 N.